Field of the Invention
The present invention relates at least in part to a sensing circuit for sensing capacitance of a sensing capacitor and a touch sensor including the same.
Discussion of the Related Art
Inputs to a touch sensor may include a driving signal input from a capacitance between a driving electrode and a sensing electrode of a touch panel, and a noise signal input from the capacitance between an object (e.g., a finger) touching the touch panel and a sensing node of the touch panel. A sensed signal may be or comprise the overlap of the two signals.
A sensing unit of the touch sensor senses variation(s) in the mutual capacitance of the touch panel. In addition, the touch sensor includes a digital processor that digitally processes the sensed mutual capacitance variation(s). When the digitally processed information is transmitted to firmware, the firmware calculates x and y coordinates and transmits the final touch position information to a host. The resolution of information transmitted from the digital processor may be an index of accuracy of coordinate calculation performed by the firmware.